Global verus US GSM for my mostly US + soem EU use?

I am based in the U.S. but do travel occasionally in native EU.
My U.S. phone data use is currently zero (prepaid flip phone!), as I have other data sources (home, Nexus 7), whereas it may be more in the EU, as I am away for the convenience of home wifi, etc. Still, I am looking for rather basic data use, nothing fancy.

I did look at the respective specs, not familiar enough with acronyms and industry directions..

If you are going to use att, go with the global because it'll work fine on their network. If you want to use T-Mobile go with the US version. If you use the global one on T-Mobile you will probably only get 2g data unless you are in a refarmed area.

If you are going to use att, go with the global because it'll work fine on their network. If you want to use T-Mobile go with the US version. If you use the global one on T-Mobile you will probably only get 2g data unless you are in a refarmed area.

Thanks.
Note that my phone-based data use is not important while in the U.S., but much more so when used in Europe (often sole source of data).
That's why my question goes beyond the AT-T, T- Mo debate...

I will need the Moto G that will get me the best data in Europe... which flavor though?

Thanks.
Note that my phone-based data use is not important while in the U.S., but much more so when used in Europe (often sole source of data).
That's why my question goes beyond the AT-T, T- Mo debate...

I will need the Moto G that will get me the best data in Europe... which flavor though?